Defining the Flood/post-Flood boundary in sedimentary rocks

There are three main schools of thought in creationist circles on the location of
the Flood/post-Flood boundary within the geological column. Because of controversy
over the geological column, I have used Walker’s biblical geological model1 to develop diagnostic criteria
for the boundary. Six qualitative diagnostic criteria typical of the Inundatory
Stage and five criteria associated with the Recessive Stage of the Flood are developed.
One paleoclimatic criterion is presented. Many examples of the use of the criteria
are mentioned.

Figure 1. The uniformitarian geological column and time scale.60 The three main locations that creationists have postulated for the Flood/post-Flood boundary are in the late Paleozoic, the Mesozoic/Cenozoic boundary, and in the late Cenozoic (shown in age column by arrows).

The placement of the Flood/post-Flood boundary in sedimentary rocks is important
within Flood geology. The placement of the boundary affects our view of the Flood,
such as its catastrophic extent, the detail of events, the amount and intensity
of post-Flood geological events, etc. For instance, it makes a difference whether
the boundary is in the late Cenozoic or at the Cretaceous/Tertiary boundary when
it comes to the number and variety of animals that disperse after the Flood from
ark representatives.2,3 It may also affect burgeoning creationist research
in baraminology. However, the location of the Flood/post-Flood boundary is quite
controversial. With respect to the geological column, there have been three main
schools of thought4 (figure
1).

The first believes that the Flood/post-Flood boundary is generally in the late Paleozoic.5–13 However, Robinson
has recently moved the boundary from just below the Permian into the Precambrian.14 Lowering the boundary within
the geological column is a predictable progression since some of the criteria used
to define a post-Flood environment in this school of thought, such as hardgrounds,
are also found in the early Paleozoic.15

In the case of hardgrounds, why not, instead, question whether such features require
a long period of time, and whether the unique catastrophic event of the one-year
Flood could have developed them? A creationist needs to collect as much information
as possible on hardgrounds, and then thoroughly analyze it before accepting uniformitarian
conclusions. Even if such features are difficult to fit into a Flood chronology,
it does not mean that the Flood could not form them. We still lack much knowledge
of the Flood. Even a cursory look at the definition of hardgrounds shows it to be
equivocal. There are indications of rapid formation, and enough uniformitarian ‘mysteries’
that leave room for alternative interpretations.15,16–17

The second school of thought believes the Flood/post-Flood boundary is near the
Cretaceous/Tertiary (K/T) boundary.18–22
Most, if not all, the Cenozoic strata would be post-Flood. Such a belief has spawned
other creationist hypotheses, such as the dam-breach hypothesis for the origin of
the Grand Canyon.23 The
Grand Canyon formed in ‘late Cenozoic’ time according to the uniformitarian
geological column, and therefore must have been carved in post-Flood time, according
to this school of thought.

Great tectonic uplift occurred during the Cenozoic; consequently, this school of
thought automatically postulates that most mountain ranges arose in the post-Flood
period without providing evidence. An example is the Sierra Nevada Mountains in
California, USA.24

The third school of thought believes the Flood/post-Flood boundary is near the end
of the Cenozoic.25–31 In practice, this school of thought believes
that practically all the lithified sedimentary rocks are from the Flood, and the
boundary is near, or at the surface of these rocks.

The above schools of thought represent a considerable divergence of opinion, and
as a result, contradictory concepts of the Flood have developed. All three schools
of thought have used informal criteria. No set of criteria has been published against
which the Flood/post-Flood boundary can be defined.

This article presents a set of diagnostic criteria with which to determine the Flood/post-Flood
boundary, similar to the criteria developed by Walker1 for distinguishing
various stages and phases of the Flood. The list of criteria is not exhaustive,
and there may be debate on the relevance of each criterion. The criteria are currently
qualitative, but it is hoped that further research will enable quantification.

Biblical basis for defining the Flood/post-Flood boundary

Figure 2. Walker’s biblical geological model (permission
from Tasman Walker with modification by Peter Klevberg for the length of the stages
and phases).

Because of the controversy of how the geological column fits into a Flood model,32 I will apply Walker’s1
biblical geological model for the Flood, which is similar to Froede’s model.33 Both models are based on
Scripture and reasonable deductions of what is expected in a global Flood. Walker’s
model (figure 2) is preferred because it has diagnostic criteria. Klevberg modified
the length of the Inundatory Stage to last 150 days, at which time the entire globe
was finally covered by water. Then the Floodwaters retreat off the continents during
the Recessive Stage that lasted 221 days. Walker divides each stage into phases.
Following the Flood, there was an Ice Age of roughly 700 years duration.33–35 Otherwise, general ‘uniformitarian’
conditions with no significant post-Flood catastrophism prevailed after the Flood.

The first two schools of thought would believe that a significant portion of the
strata was laid down by ‘post-Flood catastrophism.’ Some ‘catastrophes’
did indeed occur, such as the Ice Age and giant Ice Age floods.35,36 But the scale of the catastrophes in the post-Flood
catastrophism view are much more immense, possibly on the scale of the Flood itself.
There are reasons why such post-Flood catastrophism would threaten post-Flood life
on Earth.37 The dam-breach
hypothesis for the origin of the Grand Canyon seems to be one of the few ‘post-Flood
catastrophic’ hypotheses published in creationist literature.23,38 However, to account for all the erosion, sedimentation
and tectonics attributed to just the ‘Cenozoic’ would require much greater
catastrophic action than postulated by the dam-breach hypothesis. Until further
information is available on post-Flood catastrophism, Walker’s biblical geological
model, which is close to the ideas of Whitcomb and Morris,25 will be
applied.

Inundatory Stage diagnostic criteria

This section will develop criteria mainly caused by the Inundatory Stage of Walker’s
model.1 The one following will present criteria for determining Flood
strata mainly from the Recessive Stage of the Flood. Every criterion will have exceptions—nature
is complex. That is why I will provide multiple criteria. The boundary will be determined
easily in some areas, but it will be equivocal in other areas. Further refinement
of the diagnostic criteria can potentially classify these equivocal areas into either
the Flood or post-Flood period.

Thin, widespread sediments

Figure 3. Grand Canyon (view north from Mather Point, South Rim).

Early in the Genesis Flood, regional or continental scale currents would be likely.
These currents would spread sediments as a sheet over extensive areas. The sheets
would be relatively thin vertically. Due to erosion, some of these widespread layers
may have been dissected into remnants. However, these remnants should match lithologically
across the eroded regions.

In areas with stacked sedimentary sheets, little evidence of erosion between layers
would be observed, since the sediments were deposited rapidly.39 Although the Flood could erode channels in depositional
layers, channels should be rare. On the other hand, one would expect extensive erosion
with many deep channels cutting practically all bedding planes if the sediments
were laid down over millions of years. When we examine sedimentary rocks, we rarely
observe channels at bedding planes or boundaries between layers, such as in the
Grand Canyon (figure 3). The contacts between sedimentary formations are sometimes
razor sharp over large areas (figure 4). Such a signature is a theme worldwide.39
What better direct evidence is there for the Genesis Flood? The Flood boundary would
be above these stacked sedimentary rock layers.

Figure 4. Knife-sharp contact between the Coconino Sandstone (light)
and Hermit Shale (dark lower) of the Grand Canyon (view southwest from viewpoint
just east of North Rim Lodge). Note the flat upper contact with the Toroweap Formation.
These contact relationships exist throughout the Grand Canyon. The Coconino Sandstone
is suppose to be a wind-blown desert deposit, but what desert deposit today possesses
such a flat lower contact over such a large area, and if covered by more sediments,
would form a flat upper contact? It is unlikely the Coconino Sandstone is aeolian.

Post-Flood sedimentation would be local with a two-dimensional aspect, such as deposition
along a flood plain, along the continental shelf as spread by long-shore currents,
or as submarine slides perpendicular to the continental shelf. Horizontally extensive
sheets of strata would be unexpected during the post-Flood period. River deltas
are an example of three-dimensional deposition, but they are still small compared
to sedimentary layers deposited during the Flood. Besides, river deltas have a more
chaotic sedimentary fabric, unlike most Flood deposits. River deltas possess abundant
cut and fill structures, slides and slumps, as observed on the Mississippi River
delta.

Huge volume

Sedimentation today is very slow, except locally in a landslide, volcanic eruption,
or in glaciated areas. Average sediment accumulation should be nil in approximately
5,000 years since the Flood. Even landslide accumulation has a small volume. The
largest surficial landslides on the continents are only about 25 km3
in volume.40

When we examine some of the formations across the earth, the volumes of many formations
are huge. Ager made a point that some formations extend significantly farther than
most geologists realized.41
For example, the Coconino sandstone in the Grand Canyon (the white layer at the
top of figure 3) and its equivalents outside the canyon represent a volume of 41,000
km3 .42 The
Coconino sandstone and the many other large volume sedimentary layers would be laid
down during the Flood.

Lithified sediments

Sediments are converted into sedimentary rock by a combination of compaction and
the precipitation of cement around sediment grains.43 In order for the cement to work its way into the
sediments, groundwater must readily flow through the pore spaces. Calcite and silica
are the main cementing agents; iron oxides, other carbonate minerals, and clay minerals
are minor agents. Thus, dissolved ions of mainly calcite and silica must flow through
the pore spaces and precipitate in the voids between the grains. The grains themselves
can be disintegrated in the lithification process by solution and then be redeposited
as cement.

Flood deposition would rapidly deposit thick sediments, which would compact rapidly.
The floodwaters would have contained dissolved substances in high concentrations,
calcite and silica likely being common minerals in solution. When first deposited,
sediments would be saturated with ion-charged water. The weight of the rapidly deposited
sediments would force the water out of the sediments with increasing hydraulic pressure.
As the water is forced through the sediments, rapid flow of water would result in
rapid lithification. It is of course expected that lithification would be incomplete
in some sediments due to either a lack of compaction or insufficient cementing agents.

In the post-Flood environment, both compaction and cementing agents would be lacking.
Few, if any, post-Flood environments would collect thick sediments for significant
compaction. Groundwater moving through the sediments likely would lack cementing
agents. Thus, lithification would be expected to be local at best after the Flood.

Therefore, lithified sedimentary rocks would be a good criterion for distinguishing
between Flood and post-Flood deposits. The Flood/post-Flood boundary would be above
the lithified sediments. I emphasize above because some of the unconsolidated
sediments above the lithified sediments may be from the Flood.

The cementing of sediments is actually a uniformitarian problem today. Pettijohn
states that in the lithification of a 100-m thick layer of sand, 25–30 m of
cement must be deposited within the pore spaces (assuming little compaction).44 But the origin of this
cement, and how and when the sediment is cemented, is unresolved:

‘Cementation, moreover, is the last step in the formation of the sandstone,
and our knowledge is incomplete and unsatisfactory unless the origin and manner
of emplacement of the cement are fully understood … The problems of how and
when sands become cemented and the source of the cementing material are still unresolved.’45

The same problem of lithification of sandstone, as well as other sediments (except
possibly carbonates) would also occur in the post-Flood environment.

Permineralized fossils

An organism must first be buried rapidly to become a fossil. Otherwise predators,
scavengers and the many biological and mechanical processes will destroy the remains.46 Even the shells of marine
organisms degrade rapidly, since the shell is made up calcium carbonate held together
by a network of organic tissue. Once the organic tissue is degraded, the
shell falls apart. Raup and Stanley noted:

‘As soon as an oyster or other mollusc dies, its shell is subject to deterioration
resulting from attack by a great variety of boring organisms, including worms, sponges,
other molluscs, and algae. Most sea bottoms on which living shelled organisms are
abundant have surprisingly few intact, empty shells.’47

Even if an organism is buried rapidly, it is not guaranteed to become a fossil.
Biological and chemical degradation, even of hard parts, continues within
the sediment.

Even if an organism is buried and protected from biological and chemical decomposition,
it still must be fossilized. Organic matter must be replaced, or the spaces between
organic matter must be filled by inorganic chemicals. This process is called permineralization
(the rarer fossilization mechanisms, like carbonization, will not be discussed).
Calcium carbonate and silica are the most common chemicals that cause permineralization.48 They are also the most
common cementing agents for sediments. The replacement process must act quickly,
or else even the bones and shells decay. In the world today, modern ground water
is too low in silica;49
as a result, permineralization, as well as lithification of sediments, is rare.

On the other hand, organisms can become fossilized rapidly during the Genesis Flood.
Similar to the lithification of sediments, rapid deposition of water-saturated sediment
would cause chemically charged water to pass through the sediment pores under high
pressure. These chemicals would cause rapid permineralization and explain the billions
of fossils, the beautiful state of preservation of some fossils and the fossilization
of huge graveyards of organisms, such as dinosaurs50 and fish51
over many thousands of square kilometres. Most dinosaur remains are permineralized,
so most dinosaurs were very likely buried in the Flood. Exceptions can occur, possibly
due to a lack of cementing chemicals. An interesting example is a generally unpermineralized
T. rex unearthed from northeast Montana.52,53

Therefore, the Flood could cause rapid fossilization, while the conditions would
be rare in the post-Flood period. Raup and Stanley conclude:

‘The more we investigate the difficulties of fossil preservation, the more
surprised we become that the fossil record is as good as it is … it has been
suggested in this chapter that geologically unusual or even catastrophic conditions
contribute to the preservation of fossils. But to what degree? We do not have enough
information yet to answer this question.’54

We can thus use the vastly different fossilization potentials of the Flood and post-Flood
period to define the boundary separating the two. A permineralized fossil is likely
from the Flood, while one that is surficial and not permineralized likely would
be from post-Flood time.

Thick, pure coal seams

Figure 5. Part of Wyodak coal seam just east of Gillette, Wyoming, in the Powder River Basin.

Coal is not expected to form after the Flood in any significant quantities.55 Thick and widespread coal
seams of nearly pure, low ash coal seem impossible to form under uniformitarian
or post-Flood conditions.30,56
There are many coal layers in the ‘early Cenozoic’; e.g. in the Powder
River Basin of northeast Wyoming and southeast Montana (figure 5). Some of these
nearly pure coal seams extend about 100 km north-south, 25 km east-west, and range
up to 75 m thick in the Powder River Basin! 75 m of coal represents about 500 m
of almost pure peat, if the ratio of peat to coal thickness is 7 to 1. How could
such a thick layer of peat develop, subside slowly and be protected from all the
vicissitudes of weather, stream deposition and other factors that would impinge
on such a peat bed over millions of years, or in the post-Flood period?

It is uncertain how such huge coal beds formed during the Flood, but large-scale
Flood catastrophism at least has the scale and potential to explain such
unique deposits. Uniformitarianism seems hopeless; modern analogs are woefully inadequate.
Thus, coal seams, especially if they are pure and of large volume, would be a good
criterion for Flood deposition. The Powder River coal seams also imply that the
Flood/post-Flood boundary is at least above the ‘early Cenozoic’ of
the geological column in this area.

Widespread and/or thick ‘evaporites’

Evaporites form slowly today and cover small areas. So, one would not expect to
see evaporites of significant volume formed in the post-Flood period. Some of the
‘evaporites’ in the rock record are huge, covering tens of thousands
of km2 and are over 1 km thick. Such deposits are likely precipitates
from the Flood. For instance, an ‘evaporite’ layer found in and around
the Mediterranean Sea covers 2.5 million km2up to 1.8
km deep.57 Such
a deposit is attributed to the ‘Messinian salinity crisis’ in which
the Mediterranean Sea supposedly dried out numerous times. Some now question whether
the Mediterranean Sea dried out at all.58
Regardless, it is very difficult to conceive of the Mediterranean Sea drying in
the post-Flood period, or that any widespread, thick ‘evaporite’ was
deposited after the Flood. The Flood/post-Flood boundary must be stratigraphically
above the ‘late Miocene’ date of this deposit in the Mediterranean Sea
area. This would put the boundary near the upper part of the ‘late Cenozoic’.

Another very thick ‘evaporite’ of only about 200 km2 in area
occupies the Hualapai basin of northwestern Arizona, just west of the Grand Wash
Cliffs southeast of Lake Meade.59
This deposit is ‘nonmarine’ halite or salt that is 2.5 km thick! It
is dated as Miocene, but it defies common sense to place this thick ‘evaporite’
in the post-Flood period. The Flood/post-Flood boundary must be above this ‘evaporite’
in this area. Assuming the geological column, the boundary would be in the upper
part of the ‘late Cenozoic’.

Table 1 presents the above six criteria generally defining the Inundatory Stage
of the Flood.

Thin, horizontally widespread sediments or sedimentary rocks

Large volume of sediment or sedimentary rocks

Lithified sediments

Permineralized fossils

Coal

Large volume of ‘evaporites’

Table 1. List of Inundatory Stage criteria.

Recessive Stage diagnostic criteria

The last major event of the Flood on the continents was the Recessive Stage of the
Flood.1 This stage began as the Sheet Flow (Abative) Phase and slowly
transformed over 221 days into the Channelized Flow (Dispersive) Phase (figure 2).
During this stage, the Floodwater rushed off the continents into the ocean basins
as the land uplifted and became more exposed.30,60
Such catastrophically flowing water would have shaped the earth’s surface
into unique landforms.

Thus, landforms created during the Recessive Stage of the Flood—the last major
event, besides the Ice Age, to impact the surface of the earth—should be evident.

Has denudation since the Flood erased these landforms? Summerfield provides a summary
of current average denudation rates versus various climates and reliefs (table 2).61 Erosion rates vary from
1.5–10 mm/1000 years for a low relief, tropical climate to 95–740 mm/1000
years for mountainous areas with high precipitation. Since the Flood ended about
4500 years ago, denudation would have been slight. Of course, there are local and
regional areas of much higher erosion, such as badlands, but badlands cover small
areas. Denudation is expected to be greater during the Ice Age, but such denudation
should not be significant.62
Thus, landforms created during the Recessive Stage of the Flood—the last major
event, besides the Ice Age, to impact the surface of the earth—should be evident.
Since the landforms were carved by a catastrophic flow of water, one would expect
that uniformitarian or post-Flood processes would be inadequate to explain the landforms,
although many uniformitarian hypotheses are in the literature. In fact, these unique
Flood-derived landforms could be used to test whether significant post-Flood catastrophism
has occurred.

Mountainous

Rough

Smooth

High Precipitation

2,100

370

90

Low Precipitation

1,040

370

90

Tropical

30

Subarctic

60

Table 2. Average denudation rate in millimetres over 5,000 years with respect to
climate and relief.61

Abundant evidence exists for the Recessive Stage of the Flood.30,63,64
There is a long history of failed uniformitarian hypotheses to explain many types
of landforms, such as tall erosional remnants, planation surfaces, water gaps, inselbergs,
pediments, submarine canyons, continental shelves and slopes, and other features
of the earth’s surface.30,60,64–66 There are no post-Flood hypotheses for
the formation of these features, except for the Grand Canyon water gap. I will briefly
discuss some of these features in relation to the Flood/post-Flood boundary.

Figure 6. Devils Tower, northeast Wyoming, stands 245 m above the
surrounding plains and 400 m above the rivers of the region. This well-jointed igneous
rock, the throat of a volcano, was once covered by sedimentary rocks. The Tower
could not have remained standing for the tens of millions of years the plains were
eroding all around. It is more indicative of rapid sheet erosion of the plains that
left behind a few harder remnants. (From Oard,36 p. 75).

Figure 7. Ship Rock, northwest New Mexico, stands 520 m above a
wide valley. It too is an igneous erosional remnant that is the throat of a volcano,
like Devils Tower. (From Oard,36 p. 75).

Tall erosional remnants demonstrate rapid continental erosion

Great denudation of the western United States has occurred. More than 300 m of sedimentary
rock has been stripped from the High Plains of Montana and Wyoming. A few kilometres
of strata likely were removed from southern Arizona.31 Erosional remnants
of this great denudation were sometimes left behind.

One of the best indicators of rapid erosion is Devils Tower, northeast Wyoming (figure
6). All the plains strata surrounding the tower were eroded during more than 40
million years of geological time. But the tower continues to stand, almost untouched
by erosion! I would expect Devils Tower to be a pile of boulders in less than 100,000
years, especially in view of freeze-thaw weathering. Notice in figure 6 that the
igneous rocks of Devils Tower are well jointed. Water would lodge in the cracks,
freeze, and break up the well-joined monument in a relatively short time. Devils
Tower is better explained by a wide current of water associated with the Flood rapidly
eroding the plains sedimentary rocks, but leaving behind more resistant rocks.64

There are many other erosional remnants in the western United States, such as Ship
Rock in northwest New Mexico that is 520 m high (figure 7), Pumpkin Buttes in the
center of the Power River Basin, Square Butte in central Montana, and the Cypress
Hills in southeast Alberta and southwest Saskatchewan, Canada.

It then follows that the sedimentary rocks left behind after the great
continental denudation are from the Flood. Therefore, the strata surrounding these
remnants are from the Flood. Relative dating of all these erosional remnants would
favor a general Flood/post-Flood boundary in the late Cenozoic of the geological
time scale.

It was because of many thousands of metres of deposition of the Green River Formation
and equivalent formations over a huge area in southwest Wyoming and northeast Utah,
followed by over 600 m of denudation in much of the area, that especially
persuaded me that these formations were laid down in the Flood.67

Planation surfaces and pediments

Figure 8. The flat surface on top of Cypress Hills at Upper Battle
Creek. Surface has been partially dissected, likely from glacial meltwater rivers,
since large crystalline boulders were found within the valley. (From Oard et
al.,73 p. 80).

Planation or erosion surfaces are one of the strongest evidences demonstrating that
the Flood really occurred.60-66 A planation surface is a flat erosion
surface. According to the Dictionary of Geological Terms, an erosion surface
is defined as: ‘A land surface shaped and subdued by the action of erosion,
esp. by running water. The term is generally applied to a level or nearly level
surface.’68 Running
water is involved because planation surfaces are often capped by rounded rocks.
A pediment is a type of planation surface formed at the foot of a mountain or ridge.
A pediment is officially defined as: ‘A broad sloping erosion surface or plain
of low relief, typically developed by running water, in an arid or semiarid region
at the base of an abrupt and receding mountain front.’69 Pediments are not restricted to just semiarid
environments. As the Floodwaters rushed off the continents, planation surfaces would
form over large areas (figure 8).

Figure 9. Well-rounded quartzite rocks on top of the Teton Mountains transported from around 320 km to the northwest. (From Oard et al.,73 p. 87).

The significant aspect of planation surfaces, as well as pediments, is that they
are not forming today, except on a very small scale when a river erodes its banks.
Rivers and streams are actively destroying planation surfaces, but planation
surfaces are common and worldwide, indicating a global Flood. Some planation
surfaces cover thousands of km2 . Thus, sedimentary rocks below planation
surfaces and pediments would be Flood rocks. Since planation surfaces commonly formed
in the middle to upper Cenozoic,70
assuming the geological column, the Flood/post-Flood boundary must be in the late
Cenozoic in many areas.

It is inconceivable that planation surfaces and pediments could be formed after
the Flood. In fact, abundant planation surfaces and pediments are strong evidence
against significant post-Flood catastrophism.

Long-transported cobbles and boulders

If resistant rocks from a known location are found much too far for modern transport
processes, they likely would have been transported during Flood runoff. Peter Klevberg,
John Hergenrather, and I have traced the location of well-rounded quartzite boulders
for distances greater than 1,000 km from their known source in the Rocky
Mountains.71–77 Such long transported rocks are known from
around other mountain ranges.31,64

The location of some of the cobbles and boulders further reinforces the Flood interpretation.
For instance, some rounded cobbles are found on plateaus and at least four mountain
ranges of the northwest states (figures 9–12). Not only are the coarse gravels
from the Flood, but the rock below the gravel would also be from the Flood or before
the Flood.

One must be careful with pediment gravel. The gravel on top of a pediment may be
the veneer of cobbles and boulders left over from the time the pediment was cut
by the Flood. On the other hand, the cobbles and boulders could be post-Flood from
the surrounding mountains. Post-Flood deposits would be described as an alluvial
fan or coalesced alluvial fans, called a bajada. However, the difference should
be rather evident. The fabric and geomorphology of the deposit should determine
how the pediment gravel was deposited. Alluvial fans are generally fan shaped extending
out from a mountain valley. The fabric of the fan should be more chaotic with many
angular rocks and fine-grained interbeds. Pediment gravel from the Flood likely
would be more rounded and massive. Flood gravel may contain a proportion of exotic
clasts from lithologies that do not outcrop in the mountains above the pediment.

Figure 12. Well-rounded quartzite cobbles from on top of Gold Hill, Blue Mountains, 45 km north of Burns, central Oregon. The mountain is called Gold Hill because gold is also found within the quartzite gravel (photo by John Hergenrather). (From Oard et al.,74 p. 73).

A water gap is: ‘A deep pass in a mountain ridge, through which a
stream flows; especially a narrow gorge or ravine cut through resistant rocks by
an antecedent stream.’78
An antecedent stream is one of three main uniformitarian hypotheses for the formation
of water gaps. A wind gap is: ‘A shallow notch in the crest or upper part
of a mountain ridge, usually at a higher level than a water gap.’79 The notch in a ridge usually has to be an erosional
notch, not a notch caused by faulting or some other mechanism. In other words, the
entire ridge was once at the same altitude, and some mechanism eroded a notch in
the top of the ridge.

The existence of water and wind gaps is another one of those geomorphological features
that are difficult to explain within the uniformitarian paradigm.64 There
are well over 1,000 water gaps over the Earth. Figure 13 shows the Shoshone water
gap near Cody, Wyoming, that is 760 m deep through the Rattlesnake Mountains, east
of Yellowstone National Park, USA. It appears that the river continued to flow straight
east and somehow cut through the mountains, when the river could have easily passed
around the mountain range to the south. Figure 14 shows Buffalo Bill Reservoir west
of the water gap. A dam had to be built south of the reservoir to keep the water
from flowing south.

Water and wind gaps could easily form during the Recessive Stage of the Flood, in
particular the Channelized Phase of the Flood when Flood currents flowed perpendicular
to a ridge. Such flow can easily erode a notch in a short time that would become
a wind or water gap after the Flood. An analog for the formation of water and wind
gaps occurred during the Lake Missoula flood when water overtopped a ridge and excavated
two vertical walled canyons 150 m deep.64,80,81 Instead of flowing west
into the Columbia River as before, the Palouse River at the end of the Lake Missoula
flood took a left hand turn and now flows through one of the gaps into the Snake
River. Devils Coulee, the other gap cut in the ridge, has an obstruction at its
entrance and, therefore, is a wind gap.

Since water and wind gaps are typical Flood carved features, the Flood/post-Flood
boundary would include any feature that can be relatively dated with respect to
these geomorphic features. In other words, any strata that were deposited or eroded
before the cutting of the water and wind gap would be from the Flood. For instance,
there are 300 water gaps in the Zagros Mountains that are as deep as 2,500 m.82 The formation of the mountains
cut by these water gaps would have been during the Flood. The Zagros Mountains are
dated as Pliocene or late Cenozoic, so the Flood/post-Flood boundary would
be somewhere in the Pleistocene in this region.

Some creationists automatically assume the Pleistocene refers to the Ice Age and
must be post-Flood. However, much Pleistocene strata is unrelated to the Ice Age
or any obvious surficial post-Flood process. Pleistocene strata in many cases are
just a continuation of Cenozoic strata that have been dated by certain index fossils.
To determine whether Pleistocene strata are Flood or post-Flood, every case must
be evaluated by diagnostic criteria. Based on careful analysis of many geological
features, Holt concluded that the Flood/post-Flood boundary generally occurs in
the mid Pleistocene and that practically all the sedimentary rocks are from the
Flood:

‘Evidences … place the Flood/post-Flood boundary during or after the
mid-Pleistocene. It is not clear how the evidences presented could be interpreted
in a different manner.

Figure 13. Shoshone water gap, near Cody, Wyoming (view west). This gap is 760 m deep through the Rattlesnake Mountains, east of Yellowstone National Park, USA.

Figure 14. Buffalo Bill reservoir and view southeast from the other
side of the water gap (arrow). A dam had to be built so the water from the reservoir
would not spill southward.

‘The Flood/post-Flood boundary is near the surface of the Earth’s sediments,
independent of one’s viewpoint of the geological column … ’83

Continental margins

The debris eroded from the continents during sheet erosion has to go somewhere.
This sediment would continue to move off the uplifting continents as a sheet, until
the currents decreased upon reaching deeper water at the edge of the continents.
The velocity drop would be similar to water moving through a narrow pipe and suddenly
coming to a wide pipe. The areas of deeper water would be at the edge of the continents,
called the continental margin, or in deep basins near the continental margin. Such
deep basins would include rift basins along the continental margin84 and possibly in such areas as the lower Mississippi
River Valley where very thick sedimentary rocks occur.

Thus, the continental shelf, slope and rise would be deposits from the Sheet Flow
Phase of the Recessive Stage of the Flood.85
Submarine canyons, deep erosional channels perpendicular to the coast, likely were
cut during the subsequent Channelized Phase of the Flood.64 The continental
margin sedimentary rocks are often quite thick. One of the deepest basins along
the continental margin is the Baltimore canyon trough off the central East Coast
of the United States, extending from Cape Hatteras to Long Island86 This basin covers 200,000 km2 with
a maximum depth of 18 km of continental margin sedimentary rock! Another very deep
basin is the 20 km deep Jeanne d’Arc Basin, offshore from Newfoundland, Canada.87 Except for some surficial
sediments, practically all the continental margin sedimentary rocks should be from
the Flood.64 A majority of the continental margin sediments are Cenozoic.
It is doubtful that such a thick layer of sedimentary rock with the unique geomorphological
profile of the shelf and slope could form after the Flood, ringing all the continents.
Again, the continental margin points to a Flood/post-Flood boundary in the upper
Cenozoic along the continental margin.

If a coastal sedimentary layer is part of the continental margin, the coastal strata
likely are from the Flood. Some of the Cenozoic formations along the east coast
of the United States extend into the continental margin. So, it is likely that these
sedimentary rocks are from the Flood.

Table 3 lists the five criteria generally defining the Recessive Stage of the Flood.

Tall erosional remnants

Planation surfaces and pediments

Long-transported cobbles and boulders

Water and wind gaps

Continental margins

Table 3. List of Recessive Stage criteria.

A paleoclimatic criterion

If a fossil indicates that it mostly likely lived in a warm environment, and it
is found in an area in which winter temperatures are much colder than the likely
tolerance of that organism, the fossil was deposited in the Flood. Granted, some
cases are equivocal, and in other cases, the tolerance of some organisms is broader
than their current climatic preference. The Siberian tiger is one example of the
latter. A few examples would be the finding of palm fossils or a crocodile at high
latitudes or in the continental interior at mid latitudes. Post-Flood climates in
those regions must have been cold during the winter, especially during the Ice Age
that started immediately after the Flood. It is likely that some warm climate organisms
lived close to the warm oceans immediately after the Flood, but further information
should reveal that the environment was post-Flood.

Probably the most impressive example is the finding of Cretaceous to early Cenozoic
flying lemurs, swamp cypress and other warm climate paleoflora, tortoises, alligators,
and an extinct type of crocodile from Axel Heiberg and Ellesmere Island about 80°N
in the Queen Elizabeth islands of northeast Canada88,89
A few of these fossils were unpermineralized, but most of them were permineralized.
Some of the ‘Eocene’ swamp cypress could be cut with an axe and burned.
These fossils indicate a subtropical to tropical climate while the average temperature
in the region is about–20°C with an average winter temperature of around–40°C.
Wintertime extreme minimum temperatures are probably around–55°C. It seems
obvious that such fossils are from the Flood, and that the Flood/post-Flood boundary
in the area is above the Eocene.

Post-Flood diagnostic criteria

Post-Flood diagnostic criteria are based on features that would develop within the
past 4,500 years, assuming a rapid post-Flood Ice Age of about 700 years and a ‘uniformitarian’
environment thereafter. Many features of the landscape are obviously post-Flood
and the Flood/post-Flood boundary would lie below these features. Some of these
features are surficial soils, surficial Ice Age debris, fluvial deposits from nearby
rivers or streams, surficial landslide debris, alluvial fans, shoreline or beach
features, lacustrine deposits, tarpits, surficial sand dunes, loess, peat bogs,
talus and modern reefs.

There are supposed ancient counterparts for some of these features in the sedimentary
rocks, but the surficial features are very likely post-Flood. For example, there
are claimed ice age deposits going back to over two billion years in geological
time. These deposits are questionable and better explained as gigantic submarine
landslides during the Flood.90
Ancient sand dunes and sand sheets are claimed in the southwest US, such as the
Coconino and Navajo sandstones. These sandstones display cross-beds and are likely
marine sand deposits.91,92 They are also likely from the Flood. The sharpness
of the contacts is unlike any present day sand deposits (see figure 4).

From these diagnostic criteria and the Flood diagnostic criteria, the approximate
position of the Flood/post-Flood boundary can be established in many areas.

Examples of locating the Flood/post-Flood boundary

I have already provided examples utilizing one or more criteria for locating the
Flood/post-Flood boundary. Several more will be presented.

The Shinarump Conglomerate outcrops over 260,000 km2 on the Colorado
Plateau and is only about 15 m thick.93
The formation consists of sand and rounded pebbles (figure 15). It is also lithified.
Thus, from the first three criteria presented in tables 1 and 3, the deposit is
likely from the Flood. It is dated as Mesozoic in the geological column.

Based on the criteria from tables 1 and 3, the lithified strata below the thin surficial
soils on the plains of Montana are likely from the Flood. This designation is based
on the first five criteria in table 1 and the first three criteria in table 3. The
plains strata of Montana are dated as Cretaceous and early Cenozoic.

The extensive fossil ‘forests’ of Yellowstone National Park are found
in volcanic lahars over an extensive area in eastern and northern Yellowstone Park.94 The layers are stacked
one on top of another for many hundreds of metres. The deposits are lithified, and
petrified trees (figure 16) are found at many levels in various areas, with little
if any evidence for soils. After the deposit was laid down, channelized erosion
took out over 1,000 m of the deposit in some areas. Based on criteria one to four
of table 1 and criteria one of table 3, the lahars and fossil ‘forests’
are likely from the Flood. The layers containing the fossil forests are dated as
early Cenozoic.

Figure 16. Vertical petrified tree from Yellowstone National Park, protruding about 4.5 m out of the ground. It was likely exposed during the Recessive Stage of the Flood, as per criterion 1 in table 3.

Woolly mammoth fossils are found by the millions in Siberia, Alaska, the Yukon,
and the shallow continental shelves.35,95
These mammoth bones and tusks are not permineralized. They are buried mostly
in surficial loess and reworked loess, called ‘muck’ in Alaska. Based
on Flood criterion 1 and 2 in table 1, they could be from the Flood. However, criterion
3 and 4 would say post-Flood. The woolly mammoth is mostly unearthed from surficial
wind-blown silt—a typical post-Flood deposit. So, these woolly mammoths likely
lived in the post-Flood period, which is dated as late Pleistocene in the geological
column

Summary

The three main schools of thought for the location for the Flood/post-Flood boundary,
assuming the geological column, were briefly mentioned: (1) the late Paleozoic,
(2) the Cretaceous/Tertiary and (3) the late Cenozoic. Because of controversy and
confusion over the use of the geological column within Flood geology,32
I used Walker’s biblical geological model1 and made comparisons
to the geological column.

Six Flood diagnostic criteria, mainly from the Inundatory Stage, were laid out:
(1) thin, horizontally widespread sedimentary rocks, (2) a large volume of sedimentary
rock, (3) lithified sediments, (4) permineralized fossils, (5) coal seams and (6)
a large volume of ‘evaporites.’ Five criteria from the Recessive Stage
of the Flood were presented: (1) tall erosional remnants, (2) planation surfaces
and pediments, (3) long distance transported cobbles and boulders, (4) water and
wind gaps, (5) and continental margin sediments. One paleoclimatic criterion was
developed in which organisms from a radically different climate from today would
indicate Flood deposition of that fossil. The list is not exhaustive.

There are many surficial post-Flood criteria. These were not developed, since their
post-Flood nature should be obvious in most cases. Examples of Flood sediments were
presented, such as the Coconino Sandstone, strata containing dinosaur fossils, the
coal seams of the Powder River Basin, the Messinian evaporites in the Mediterranean
Sea region, the Zagros Mountains, the Shinarump conglomerate, the plains strata
of Montana, the lahars containing the Yellowstone fossil ‘forests,’
and the warm-climate fossils on Axel Heiberg Island. The Flood/post-Flood boundary
would be above these features. The surficial woolly mammoth fossils found in loess
in Siberia, Alaska and the Yukon are likely post-Flood.

As it turns out, there are many areas of the world where the Flood/post-Flood boundary
is in the late Cenozoic. I agree with Holt’s view that the boundary is near
the surface of the sediments or sedimentary rocks at the earth’s surface in
most areas.

Acknowledgements

I thank Peter Klevberg and Carl Froede for reviewing an earlier draft of the manuscript.

Garner, P. and Peet, J., Reviews of From Flood to Pharaoh–A
Chronological Framework by Steven J. Robinson and of From Flood to Pharaoh–Understanding
the Old Stone Age by Steven J. Robinson, Origins—The Journal of the Biblical
Creation Society26:27–30, 1999. Return
to text.

Wilson, M.A., Palmer, T.J., Guensburg, T.E., Finton, C.D.
and Kaufman, L.E., The development of an Early Ordovician hardground community in
response to rapid sea-floor calcite precipitation, Lethaia25:19–34,
1992. Return to text.

Hardie, L.A. and Lowenstein, T.K., Did the Mediterranean
Sea dry out during the Miocene? A reassessment of the evaporite evidence from DSDP
legs 13 and 42A cores, Journal of Sedimentary Research74
(4):453–461, 2004. Return to text.